Yes, the preliminary (1963) ASCII had an up arrow instead of the caret and a left arrow instead of the underline. DEC, Xerox and others built equipment around the 1963 draft and failed to change when the final version of ASCII came out. That is why when Pascal and Smalltalk came along later they used the "wrong" characters.
In the case of Smalltalk, it was Digitalk's "Methods" (the precursor of Smalltalk/V) that adopted := for assignment in place of the left arrow (though the IBM PC character set actually had one, just not with the same code as ASCII 1963) since all of its tutorials were aimed at Pascal programmers.
In the case of Smalltalk, it was Digitalk's "Methods" (the precursor of Smalltalk/V) that adopted := for assignment in place of the left arrow (though the IBM PC character set actually had one, just not with the same code as ASCII 1963) since all of its tutorials were aimed at Pascal programmers.